CPU Panic when Mailbulter installed on OSX Cataline

After I installed Catalina, the Mac crashed with frequent CPU panics. I uninstalled the program and the problems stopped, so I assumed that Mailbutler was the issue and resigned myself to living without it. Recently, having read there was an update that now worked with Catalina, I reinstalled, but this time, while the Mac doesn’t crash while I’m using it and appears to shut down correctly, but on every restart it reports there has been a CPU panic. I’m getting ready to carefully uninstall it again, but wondered if anyone else is having this problem and has found a solution. I’m running the latest version downloaded from the site (2428).